Chronic exposure to ultraviolet B rays (UVB: 290-320 nm wavelength), or solar rays, in general (comprising, among other wavelengths, that of UVB radiation) produces skin aging (photoaging) due to the accumulation of DNA damage and on the structural proteins of the skin, evidencing in the form of fine wrinkles, laxity with loss of skin elasticity, elastosis, yellowish staining with localizad areas of melanin hyperpigmentation (solar, actinic or senile lentigo). Besides, skin photoaging is associated with the appearance of comedoes that are more evident in the “cutis romboidalis” at the rear part of the neck. In the histological test, an epidermic atrophy and degenerative changes in elastic fibers of the dermis may be observed (Pearse A D, Gaskell S A, Marks R. J Invest Dermatol 1987; 88 83-87; Berton T R, Mitchell D L, Fischer S M, Looniskar M F. J Invest Dermatol 1997; 109: 340-347). Furthermore, chronic exposure to UVB rays is a risk factor for the appearance of benign lesions, such as seborrheic keratosis, and premalignant lesions such as actinic keratosis (Kripke M L. Cancer Res 1994; 54: 6102-6105). Currently, there is no effective treatment for skin photoaging (Dermatol Surg. Special Issue: Cosmeceuticals. Invited editors: Draelos Z D, Brody H J. 2005).
On the other hand, the hair follicle is the functional unit for hair elongation. Hirsutism is a clinical condition in which there in an excessive hair growth with an androgenic-type pattern (face, thorax, areolas, linea alba, lower part of the back, buttocks, limbs and external genitals) produced by an increase in the androgenic activity. Hypertricosis is a condition in which there is an excessive hair growth in areas sensitive and non-sensitive to androgens.
Obesity is a disease produced when the energy intake exceeds and produces an excess of adipose tissue. This process is regulated by the control on the intake, on the energy expenditure and efficiency and on the adipogenesis). (Gregoire F M. Exp Biol Med, 2001, 226: 997-1002; Palou A et al. Eur J Nutr, 2000, 39: 127-144). Prevention and/or treatment of obesity is a very important factor to reduce morbidity and mortality rates associated to cardiovascular disorders and to type 2 diabetes, which represent a high health and social cost in industrialized countries. Currently, there is no effective treatment for obesity. The effective therapies to treat obesity should interfere with the development of adipose tissue. To increase the adipose tissue mass, it is essential that preadipocytes are differentiated in a mature adipocyte phenotype. Besides morphological changes, the differentiation process of preadipocyte into adipocyte is accompanied by metabolic processes such as the capacity of storing energy in the form of triglycerides (McDougald O A, Lane M D. Annu Rev Biochem, 1995, 345-373; Spiegelman B M, Flier J S. Cell 1996, 87: 377-389). Therefore, the pharmacological inhibition of the differentiation of preadipocytes into adipocytes represents a therapeutic strategy to treat obesity.
There is a need to find alternative treatments to the current ones for skin photoaging, hirsutism, or obesity; both from the aesthetic and therapeutic points of view, based on the use of active principles.